Design And Dynamic Characteristics Analysis Of Timing Silent Chain System For V6 Gasoline Engine

With the development of automotive technology,the performance requirements of automotive engine are also improving.The silent chain with low noise and small vibration is applied more and more widely in engine timing valvetrain and other power transmission mechanisms.However,the domestic chain industry is in the early stage about the timing silent chain system development and application for engine,the capability of independent design,research and development is insufficient.Presently,the core technology of the timing chain system design has been monopolized by foreign chain system design companied and manufacturers.Based on the reading and analysis of the domestic and foreign papers related engine timing chain system design,simulation analysis,performance test and evaluation,aiming at the design and analysis technology of multi axis and multi layers layout,low noise,light wear and high reliability life chain system of automotive engine,for the design of a V 6-cylinder gasoline engine timing silent chain system,the following works were carried out:Firstly,according to the characteristics of the engine layout and the requirements of the structure and installation,a layout design scheme for the timing chain system which meets the design requirements is proposed.Secondly,a new silent chain with pitch 6.35 mm and sprockets tooth profile are designed and developed,and a detailed chain link plate and sprocket tooth profile that can achieve NVH performance is determined through analyzing the engaging transmission process of the silent chain and sprockets.Finally,the multi-body dynamics simulation model of the multi-layer and multi axised timing chain drive system of the V type 6-cylinder turbocharged direct injection gasoline engine is build,the dynamic response characteristics of the timing chain system under different speeds and load conditions are analyzed.The variation law of the chain tension and the reaction force of the hydraulic tensioner plunger are studied,and the layout scheme of the timing silent chain satisfying the engine design requirements is put forward.In conclusion,the paper research results provide theoretical basis,design and development experience for realizing the self-development of multi-axis and multi-layer timing chain system in China.